This study was conducted to investigate the effects of dietary ME and CP levels on laying performance, egg quality and serum biochemical indices of Fengda-1 layers. In a 2 × 3 factorial arrangement, 2,400 Fengda-...This study was conducted to investigate the effects of dietary ME and CP levels on laying performance, egg quality and serum biochemical indices of Fengda-1 layers. In a 2 × 3 factorial arrangement, 2,400 Fengda-1 layers(32 wk of age) were randomly assigned to 6 experimental diets with 2,650 and 2,750 kcal of ME/kg of diet, each containing 14.50%, 15.00% and 15.50% CP, respectively. Each dietary treatment was replicated 5 times, and feed and water were provided ad libitum. The trial lasted for 10 wk, including a2-week acclimation period and an 8-week experimental period. Our results showed that ADFI decreased as the ME level of diet increased from 2,650 to 2,750 kcal/kg(P< 0.05). Layers fed diets with 2,750 kcal/kg ME exhibited higher mortality than those fed with 2,650 kcal/kg ME(P < 0.05). Birds fed with 14.50% and15.00% CP had higher egg production(EP) and egg mass(EM) than those fed with 15.50% CP(P < 0.05).Yolk color increased as the ME level of the diet increased from 2,650 to 2,750 kcal/kg, however, the eggshell thickness decreased(P < 0.05). Serum concentrations of uric acid and triglyceride in layers fed diets with 2,750 kcal/kg ME were higher than those fed diets with 2,650 kcal/kg ME(P < 0.05). There was no significant interaction between ME and CP on laying performance, egg quality, or serum biochemical indices(P > 0.05). Based on the data under the experimental conditions, the optimal dietary ME and CP levels of Fengda-1 layers are 2,650 kcal/kg and 15.00%(33 to 41 wk of age).展开更多
ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these material...ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.展开更多
In copper oxide (CuO) based solar cells, various buffer layers such as CdS, In<sub>2</sub>S<sub>3</sub>, WS<sub>2</sub> and IGZO have been investigated by solar cell capacitance sim...In copper oxide (CuO) based solar cells, various buffer layers such as CdS, In<sub>2</sub>S<sub>3</sub>, WS<sub>2</sub> and IGZO have been investigated by solar cell capacitance simulator (SCAPS) in this work. By varying absorber and buffer layer thickness, photovoltaic parameters (open circuit voltage, fill factor, short-circuit current density and efficiency) are determined. The highest efficiency achieved is 19.6% with WS<sub>2</sub> buffer layer. The impact of temperature on all CuO-based solar cells is also investigated.展开更多
The AlGaN-based deep ultraviolet light-emitting diodes（LED） with double electron blocking layers（d-EBLs） on both sides of the active region are investigated theoretically. They possess many excellent performances ...The AlGaN-based deep ultraviolet light-emitting diodes（LED） with double electron blocking layers（d-EBLs） on both sides of the active region are investigated theoretically. They possess many excellent performances compared with the conventional structure with only a single electron blocking layer, such as a higher recombination rate, improved light output power and internal quantum efficiency（IQE）. The reasons can be concluded as follows. On the one hand, the weakened electrostatic field within the quantum wells（QWs） enhances the electron–hole spatial overlap in QWs, and therefore increases the probability of radioactive recombination. On the other hand, the added n-AlGaN layer can not only prevent holes from overflowing into the n-side region but also act as another electron source, providing more electrons.展开更多
LiNi1/3Co1/3Mn1/3O2 was coated with uniform nano-sized AlF3 layer by chemical precipitation method to improve its rate capability.The samples were characterized by X-ray diffractometry (XRD),transmission electron micr...LiNi1/3Co1/3Mn1/3O2 was coated with uniform nano-sized AlF3 layer by chemical precipitation method to improve its rate capability.The samples were characterized by X-ray diffractometry (XRD),transmission electron microscopy (TEM),energy dispersive spectroscopy (EDS),charge-discharge cycling,cyclic voltammetry (CV),and electrochemical impedance spectroscopy (EIS).Uniform coated layer with a thickness of about 3 nm was observed on the surface of LiNi1/3Co1/3Mn1/3O2 particle by TEM.At 0.5C and 2C rates,1.5% (mass fraction) AlF3-coated LiNi1/3Co1/3Mn1/3O2/Li in 2.8-4.3 V versus Li/Li+ after 80 cycles showed less than 3% of capacity fading,while those of the bare one were 16.5% and 45.9%,respectively.At 5C rate,the capacity retention of the coated sample after 50 cycles maintained 91.4% of the initial discharge capacity,while that of the bare one decreased to 52.6%.EIS result showed that a little change of charge transfer resistance of the coated sample resulting from uniform thin AlF3 layer was proposed as the main reason why its rate capability was improved obviously.CV result further indicated a greater reversibility for the electrode processes and better electrochemical performance of AlF3-coated layer.展开更多
In this paper we report that the GaN thin film is grown by metal-organic chemical vapour deposition on a sapphire （0001） substrate with double A1N buffer layers. The buffer layer consists of a low-temperature （LT）...In this paper we report that the GaN thin film is grown by metal-organic chemical vapour deposition on a sapphire （0001） substrate with double A1N buffer layers. The buffer layer consists of a low-temperature （LT） A1N layer and a high-temperature （HT） A1N layer that are grown at 600 ℃ and 1000 ℃, respectively. It is observed that the thickness of the LT-A1N layer drastically influences the quality of GaN thin film, and that the optimized 4.25-min-LT-A1N layer minimizes the dislocation density of GaN thin film. The reason for the improved properties is discussed in this paper.展开更多
High-quality MgxZn1-xO thin films were grown on sapphire（0001 ） substrates with a ZnO buffer layer of different thicknesses by means of metal-organic chemical vapor deposition. Diethyl zinc, bis-cyclopentadienyl-Mg ...High-quality MgxZn1-xO thin films were grown on sapphire（0001 ） substrates with a ZnO buffer layer of different thicknesses by means of metal-organic chemical vapor deposition. Diethyl zinc, bis-cyclopentadienyl-Mg and oxygen were used as the precursor materials. The crystalline quality, surface morphologies and optical properties of the Mg, Zn1-xO films were investigated by X-ray diffraction, atomic force microscopy and photoluminescence spectrometry. It was shown that the quality of the MgxZn1-xO thin films depends on the thickness of the ZnO buffer layer and an Mg, Zn1-xO thin film with a ZnO buffer layer whose thickness was 20 nm exhibited the best crystal-quality, optical properties and a flat and dense surface.展开更多
A new coordination polymer [Cd（bimc）2]n was obtained by the reaction of Hbimc with Cd（NO3） 2·4H2O in NaOH solution, and characterized by elemental analysis, IR and singlecrystal X-ray diffraction. The crystal...A new coordination polymer [Cd（bimc）2]n was obtained by the reaction of Hbimc with Cd（NO3） 2·4H2O in NaOH solution, and characterized by elemental analysis, IR and singlecrystal X-ray diffraction. The crystal belongs to orthorhombic, space group Pbcn with a = 12.533（4）, b = 15.705（5）, c = 15.200（5） A, V= 2991.8（15） A^3, Mr = 434.68, Z = 8, Dc = 1.930 g/cm^3, F（000） = 1712,μ（MoKa） = 1.492 mm^-1, the final R = 0.0410 and wR = 0.0804 for 1661 observed reflections （I 〉 2σ（I））. The Cd atom exhibits a distorted six-coordinate CdNzOa octahedral coordination geometry. The complex molecules are linked by both μ2-（η2-O, O^-）, NI and μ2-（η2-O, O^-）, N3 coordination modes of ligands to form cross-like wave （4, 4） layer structures which are further stacked through interlayer hydrogen bonds and π-π stacking interactions in an offset fashion to form a 3D supramolecular structure.展开更多
In this study, the authors investigated the performance of different buffer layers through the electrical parameters such as J<sub>sc</sub>, V<sub>oc</sub>, QE and η of the quaternary system C...In this study, the authors investigated the performance of different buffer layers through the electrical parameters such as J<sub>sc</sub>, V<sub>oc</sub>, QE and η of the quaternary system Cu(In,Ga)Se<sub>2</sub> solar cells. The performance of Cu(In,Ga)Se<sub>2</sub>solar cells has been modeled and numerically simulated by using the SCAPS- 1D device simulation tool. The cells with a ZnSe, Zn(O,S) and (Zn,Mg)O buffer layers were compared with the reference CdS buffer layer. The investigation of ZnSe, Zn(O, S) and (Zn,Mg)O-based cells to substitute the traditional CdS in the future shows that the ZnSe-buffer layer is a potential material to replace CdS, which revealed the best efficiency of 20.76%, the other electrical parameters are: J<sub>SC</sub> = 34.6 mA/cm<sup>2</sup>, V<sub>OC</sub> = 0.76 V and FF = 79.6%. The losses as a function of the temperature are estimated at 0.1%/K, among all kinds of buffer layers studied. We have also shown that the use of a high band-gap buffer layer is necessary to obtain a better short-circuit current density J<sub>SC</sub>. From our results, we note that the chalcogenide solar cells with Zn-based alternative buffer layer have almost the same stability thatthe traditional CdS buffer layer solar cells have.展开更多
A new ion-pair complex, [BzMeQ1]2[Ni（nmt）2]1（[BzMeQ1]^＋ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate） has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction ...A new ion-pair complex, [BzMeQ1]2[Ni（nmt）2]1（[BzMeQ1]^＋ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate） has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction methods. Complex 1 is of triclinic, space group PI, with a = 9.079（2）, b = 10.154（2）, c = 11.243（2）A, α= 81.58（1）, β= 69.63（1）, γ = 68.02（1）°, V= 940.1（3）A3, Dc = 1.427 g/cm^3, Z = 1, F（000） = 418 and R = 0.0442. A 2D layer structure is formed via the cation-cation π…π and C-H…π interactions observed in the solid state of the complex.展开更多
1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralo...1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralone is still a big challenge with low-temperature processes using environmentally friendly routes even after decades of research. Herein, we demonstrate room-temperature oxidation of tetralin to 1-tetralone over layered double hydroxide-hosted sulphonato-salen-nickel(II) complex, LDH-[Ni-salen]. The layered double hydroxide-hosted sulphonato-salen-nickel(II) compound was characterized by powder X-ray diffraction, Fourier transform infrared spectrometer (FTIR), UV-Visible diffuse reflectance spectra, scanning electron microscopy (SEM) and elemental analysis. The theoretical calculations of free sulphonato-salen-nickel(II) complex using Density Functional Theory/CAM-B3LYP at the 6-311++ G(d,p) level of theory were also used to determine the orientation of the Ni-salen compound within the layered structure. The immobilized compound, LDH-[Ni-salen] was found to be an effective reusable catalyst for the oxidation of tetralin to 1-tetralone using a combination of trimethylacetaldehyde and molecular oxygen (14.5 psi) and at 25°C. At 45.5% conversion, tetralin was converted to 1-tetralone with 77.2% selectivity at room temperature and atmospheric pressure after 24 h. The catalyst recycles test and hot filtration experiment showed that oxidation proceeded through Ni(II) sites in LDH-[Ni-salen]. The catalysts were reused several times without losing their catalytic activity and selectivity. The present results may provide a convenient strategy for the preparation of 1-tetralone using layered double hydroxide-based heterogeneous catalyst at ambient temperature for industrial application in near future.展开更多
Ternary In-rich AlxIn1-x N films were successfully grown on Si （111） and （0001） sapphire substrates by radio-frequency magnetron sputtering on a relatively Al-rich AlxIn1-x N layer after AlN buffer. X-ray diffract...Ternary In-rich AlxIn1-x N films were successfully grown on Si （111） and （0001） sapphire substrates by radio-frequency magnetron sputtering on a relatively Al-rich AlxIn1-x N layer after AlN buffer. X-ray diffraction （XRD） patterns of the films indicate highly c axis-oriented wurtzite structure and the indium content of about 0.76 has been evaluated according to the Vegard＇s law. An Al-rich AlxIn1-xN transition layer was formed between the ultimate In-rich AlxIn1-x N film and the AlN buffer, which served as a further buffer to alleviate mismatch. X-ray photoelectron spectroscopy （XPS） depth profiling analyses confirm the alternative of indium and aluminum composition and the unavoidable oxygen impurities from surface to bulk. Owing to high indium content, obvious E2u and InN-like Al （LO） phonon model accompanying with slight A1N-like A1 （LO） phonon model are observed. Hall effect measurements demonstrate n-type electrical conductivity in these alloys with carrier concentrations n=1019 cm-3. The strain in In-rich AlxIn1-x N films can be significantly reduced by introducing an Al-rich interlayer, facilitating the improvement of film quality for diverse device applications.展开更多
The strain relaxation of an A1GaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of A1GaN/GaN heterostructures. Compared with the slight strain relaxation found in A1Ga...The strain relaxation of an A1GaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of A1GaN/GaN heterostructures. Compared with the slight strain relaxation found in A1GaN barrier layer without cap layer, it is found that a thin cap layer can induce considerable changes of strain state in the A1GaN barrier layer. The degree of relaxation of the A1GaN layer significantly influences the transport properties of the two-dimensional electron gas （2DEG） in A1GaN/GaN heterostructures. It is observed that electron mobility decreases with the increasing degree of relaxation of the A1GaN barrier, which is believed to be the main cause of the deterioration of crystalline quality and morphology on the A1GaN/GaN interface. On the other hand, both GaN and A1N cap layers lead to a decrease in 2DEC density. The reduction of 2DEG caused by the GaN cap layer may be attributed to the additional negative polarization charges formed at the interface between CaN and A1GaN, while the reduction of the piezoelectric effect in the A1GaN layer results in the decrease of 2DEC density in the case of A1N cap layer.展开更多
With the Uddeholm self restricted method, the effect of compound layer of plasma nitriding on thermal fatigue behavior of 4Cr5MoSiV1 steel was studied by the way of adding Ar during plasma nitriding to remove the com...With the Uddeholm self restricted method, the effect of compound layer of plasma nitriding on thermal fatigue behavior of 4Cr5MoSiV1 steel was studied by the way of adding Ar during plasma nitriding to remove the compound layer. The results show that the compound layer of plasma nitriding can delay the nucleation of heat cracks and hold back the propagation of heat cracks from surface to substrate because of its high hardness and strength. On the other land, the heat checking expands faster with the compound layer on the surface than that without it. After 3000 cycles of thermal fatigue test, both heat cracks with the compound layer are wider than the another without compound layer and the number of heat cracks of the former is more from the view of cross section.展开更多
In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with t...In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar cell.We tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction(GIXRD)technique,and then investigate the bandgap grading of the CIGS absorbing layer.When the glancing incident angle increased from 0.50 to 5.00°,the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3)to 5.6905(2)?,and 11.3917(3)to 11.2114(2)?,respectively.The depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the compositionof In or Ga with depth in the absorbing layer.The variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic site.According to the results of the depth profile of the refined parameters using GIXRD data,the bandgap of the CIGS absorber layer was graded over a range of 1.222-1.532 eV.This approach allows to determine the In or Ga gradients in the CIGS absorbing layer,and to nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.展开更多
[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin laye...[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin layer chromatography(TLC).A high performance liquid chromatography(HPLC)was established to determine the content of notoginsenoside R1 in the granule.[Results]The traditional Chinese medicinal materials in Jiedu Shengxue granules could be identified by TLC,and the characteristic spots were stable and clear.Notoginsenoside R1 had a good linear relationship in the range of 10.45-104.5μg/mL,with an average recovery of 98.52%and RSD=2.36%.[Conclusions]TLC and HPLC,as the quality control methods of Jiedu Shengxue granules,have high accuracy and good repeatability,which lays a foundation for the quality control of this mixture.展开更多
基金funded by the earmarked fund for Modern ArgoIndustry Technology Research System of China (No. CARS-41-K17)the National Key Technology R&D Program (No. 2014BAD13B04)
文摘This study was conducted to investigate the effects of dietary ME and CP levels on laying performance, egg quality and serum biochemical indices of Fengda-1 layers. In a 2 × 3 factorial arrangement, 2,400 Fengda-1 layers(32 wk of age) were randomly assigned to 6 experimental diets with 2,650 and 2,750 kcal of ME/kg of diet, each containing 14.50%, 15.00% and 15.50% CP, respectively. Each dietary treatment was replicated 5 times, and feed and water were provided ad libitum. The trial lasted for 10 wk, including a2-week acclimation period and an 8-week experimental period. Our results showed that ADFI decreased as the ME level of diet increased from 2,650 to 2,750 kcal/kg(P< 0.05). Layers fed diets with 2,750 kcal/kg ME exhibited higher mortality than those fed with 2,650 kcal/kg ME(P < 0.05). Birds fed with 14.50% and15.00% CP had higher egg production(EP) and egg mass(EM) than those fed with 15.50% CP(P < 0.05).Yolk color increased as the ME level of the diet increased from 2,650 to 2,750 kcal/kg, however, the eggshell thickness decreased(P < 0.05). Serum concentrations of uric acid and triglyceride in layers fed diets with 2,750 kcal/kg ME were higher than those fed diets with 2,650 kcal/kg ME(P < 0.05). There was no significant interaction between ME and CP on laying performance, egg quality, or serum biochemical indices(P > 0.05). Based on the data under the experimental conditions, the optimal dietary ME and CP levels of Fengda-1 layers are 2,650 kcal/kg and 15.00%(33 to 41 wk of age).
文摘ZnTe, CdTe, and the ternary alloy CdZnTe are important semiconductor materials used widely for the detection of an important range of electromagnetic radiation as gamma ray and X-ray. Although, recently these materials have acquired renewed importance due to the new explored nanolayer properties of modern devices. In addition, as shown in this work they can be grown using uncomplicated synthesis techniques based on the deposition in vapour phase of the elemental precursors. This work presents the results obtained from the deposition of nanolayers of these materials using the precursor vapour on GaAs and GaSb (001) substrates. This growth technique, extensively known as atomic layer deposition (ALD), allows the layers growth with nanometric dimension. The main results presented in this work are the used growth parameters and the results of the structural characterization of the layers by the means of Raman spectroscopy measurements. Raman scattering shows the peak corresponding to longitudinal optical (LO)-ZnTe, which is weak and slightly redshift in comparison with that reported for the ZnTe bulk at 210 cm^-1. For the case of the CdTe nanolayer, Raman spectra presented the LO-CdTe peak, which is indicative of the successful growth of the layer. Its weak and slightly redshift in comparison with that reported for the CdTe bulk can be related with the nanometric characteristic of this layer. The performed high-resolution X-ray diffraction (HR-XRD) measurement allows to study some important characteristics such as the crystallinity of the grown layer. In addition, the HR-XRD measurement suggests that the crystalline quality has dependence on the growth temperature.
文摘In copper oxide (CuO) based solar cells, various buffer layers such as CdS, In<sub>2</sub>S<sub>3</sub>, WS<sub>2</sub> and IGZO have been investigated by solar cell capacitance simulator (SCAPS) in this work. By varying absorber and buffer layer thickness, photovoltaic parameters (open circuit voltage, fill factor, short-circuit current density and efficiency) are determined. The highest efficiency achieved is 19.6% with WS<sub>2</sub> buffer layer. The impact of temperature on all CuO-based solar cells is also investigated.
基金Project supported by the Special Strategic Emerging Industries of Guangdong Province,China(Grant No.2012A080304006)the Major Scientific and Technological Projects of Zhongshan City,Guangdong Province,China(Grant No.2014A2FC204)the Forefront of Technology Innovation and Key Technology Projects of Guangdong Province,China(Grant Nos.2014B010121001 and 2014B010119004)
文摘The AlGaN-based deep ultraviolet light-emitting diodes（LED） with double electron blocking layers（d-EBLs） on both sides of the active region are investigated theoretically. They possess many excellent performances compared with the conventional structure with only a single electron blocking layer, such as a higher recombination rate, improved light output power and internal quantum efficiency（IQE）. The reasons can be concluded as follows. On the one hand, the weakened electrostatic field within the quantum wells（QWs） enhances the electron–hole spatial overlap in QWs, and therefore increases the probability of radioactive recombination. On the other hand, the added n-AlGaN layer can not only prevent holes from overflowing into the n-side region but also act as another electron source, providing more electrons.
基金Project(50542004) supported by the National Natural Science Foundation of ChinaProject(1960-71131100017) supported by Graduate Degree Thesis Innovation Foundation of Central South University,China
文摘LiNi1/3Co1/3Mn1/3O2 was coated with uniform nano-sized AlF3 layer by chemical precipitation method to improve its rate capability.The samples were characterized by X-ray diffractometry (XRD),transmission electron microscopy (TEM),energy dispersive spectroscopy (EDS),charge-discharge cycling,cyclic voltammetry (CV),and electrochemical impedance spectroscopy (EIS).Uniform coated layer with a thickness of about 3 nm was observed on the surface of LiNi1/3Co1/3Mn1/3O2 particle by TEM.At 0.5C and 2C rates,1.5% (mass fraction) AlF3-coated LiNi1/3Co1/3Mn1/3O2/Li in 2.8-4.3 V versus Li/Li+ after 80 cycles showed less than 3% of capacity fading,while those of the bare one were 16.5% and 45.9%,respectively.At 5C rate,the capacity retention of the coated sample after 50 cycles maintained 91.4% of the initial discharge capacity,while that of the bare one decreased to 52.6%.EIS result showed that a little change of charge transfer resistance of the coated sample resulting from uniform thin AlF3 layer was proposed as the main reason why its rate capability was improved obviously.CV result further indicated a greater reversibility for the electrode processes and better electrochemical performance of AlF3-coated layer.
基金Project supported by the National Key Science & Technology Special Project,China(Grant No.2008ZX01002-002)the Fundamental Research Funds for the Central Universities,China(Grant No.JY10000904009)the Major Program and State Key Program of the National Natural Science Foundation of China(Grant Nos.60890191 and 60736033)
文摘In this paper we report that the GaN thin film is grown by metal-organic chemical vapour deposition on a sapphire （0001） substrate with double A1N buffer layers. The buffer layer consists of a low-temperature （LT） A1N layer and a high-temperature （HT） A1N layer that are grown at 600 ℃ and 1000 ℃, respectively. It is observed that the thickness of the LT-A1N layer drastically influences the quality of GaN thin film, and that the optimized 4.25-min-LT-A1N layer minimizes the dislocation density of GaN thin film. The reason for the improved properties is discussed in this paper.
文摘High-quality MgxZn1-xO thin films were grown on sapphire（0001 ） substrates with a ZnO buffer layer of different thicknesses by means of metal-organic chemical vapor deposition. Diethyl zinc, bis-cyclopentadienyl-Mg and oxygen were used as the precursor materials. The crystalline quality, surface morphologies and optical properties of the Mg, Zn1-xO films were investigated by X-ray diffraction, atomic force microscopy and photoluminescence spectrometry. It was shown that the quality of the MgxZn1-xO thin films depends on the thickness of the ZnO buffer layer and an Mg, Zn1-xO thin film with a ZnO buffer layer whose thickness was 20 nm exhibited the best crystal-quality, optical properties and a flat and dense surface.
基金This work was supported by the NNSFC (No. 30460153 20561001), NSF of Guangxi Province (No. 0447019), and the Teaching and Research Award Program for Outstanding Young Teachers in Higher Education Institutions of Chinese Ministry of Education
文摘A new coordination polymer [Cd（bimc）2]n was obtained by the reaction of Hbimc with Cd（NO3） 2·4H2O in NaOH solution, and characterized by elemental analysis, IR and singlecrystal X-ray diffraction. The crystal belongs to orthorhombic, space group Pbcn with a = 12.533（4）, b = 15.705（5）, c = 15.200（5） A, V= 2991.8（15） A^3, Mr = 434.68, Z = 8, Dc = 1.930 g/cm^3, F（000） = 1712,μ（MoKa） = 1.492 mm^-1, the final R = 0.0410 and wR = 0.0804 for 1661 observed reflections （I 〉 2σ（I））. The Cd atom exhibits a distorted six-coordinate CdNzOa octahedral coordination geometry. The complex molecules are linked by both μ2-（η2-O, O^-）, NI and μ2-（η2-O, O^-）, N3 coordination modes of ligands to form cross-like wave （4, 4） layer structures which are further stacked through interlayer hydrogen bonds and π-π stacking interactions in an offset fashion to form a 3D supramolecular structure.
文摘In this study, the authors investigated the performance of different buffer layers through the electrical parameters such as J<sub>sc</sub>, V<sub>oc</sub>, QE and η of the quaternary system Cu(In,Ga)Se<sub>2</sub> solar cells. The performance of Cu(In,Ga)Se<sub>2</sub>solar cells has been modeled and numerically simulated by using the SCAPS- 1D device simulation tool. The cells with a ZnSe, Zn(O,S) and (Zn,Mg)O buffer layers were compared with the reference CdS buffer layer. The investigation of ZnSe, Zn(O, S) and (Zn,Mg)O-based cells to substitute the traditional CdS in the future shows that the ZnSe-buffer layer is a potential material to replace CdS, which revealed the best efficiency of 20.76%, the other electrical parameters are: J<sub>SC</sub> = 34.6 mA/cm<sup>2</sup>, V<sub>OC</sub> = 0.76 V and FF = 79.6%. The losses as a function of the temperature are estimated at 0.1%/K, among all kinds of buffer layers studied. We have also shown that the use of a high band-gap buffer layer is necessary to obtain a better short-circuit current density J<sub>SC</sub>. From our results, we note that the chalcogenide solar cells with Zn-based alternative buffer layer have almost the same stability thatthe traditional CdS buffer layer solar cells have.
基金the President's Science Foundation of South China Agricultural University (No. 2005K092)
文摘A new ion-pair complex, [BzMeQ1]2[Ni（nmt）2]1（[BzMeQ1]^＋ = 1-benzyl-4-ntethylquino- linium, mnta- -- maleonitriledithiolate） has been synthesized and structurally characterized by IR, ESI-MS and X-ray diffraction methods. Complex 1 is of triclinic, space group PI, with a = 9.079（2）, b = 10.154（2）, c = 11.243（2）A, α= 81.58（1）, β= 69.63（1）, γ = 68.02（1）°, V= 940.1（3）A3, Dc = 1.427 g/cm^3, Z = 1, F（000） = 418 and R = 0.0442. A 2D layer structure is formed via the cation-cation π…π and C-H…π interactions observed in the solid state of the complex.
文摘1-Tetralone, a useful synthetic intermediate in the manufacture of pharmaceuticals, agrochemicals and dyes, can be prepared by liquid phase catalytic oxidation of tetralin. Selective oxidation of tetralin to 1-tetralone is still a big challenge with low-temperature processes using environmentally friendly routes even after decades of research. Herein, we demonstrate room-temperature oxidation of tetralin to 1-tetralone over layered double hydroxide-hosted sulphonato-salen-nickel(II) complex, LDH-[Ni-salen]. The layered double hydroxide-hosted sulphonato-salen-nickel(II) compound was characterized by powder X-ray diffraction, Fourier transform infrared spectrometer (FTIR), UV-Visible diffuse reflectance spectra, scanning electron microscopy (SEM) and elemental analysis. The theoretical calculations of free sulphonato-salen-nickel(II) complex using Density Functional Theory/CAM-B3LYP at the 6-311++ G(d,p) level of theory were also used to determine the orientation of the Ni-salen compound within the layered structure. The immobilized compound, LDH-[Ni-salen] was found to be an effective reusable catalyst for the oxidation of tetralin to 1-tetralone using a combination of trimethylacetaldehyde and molecular oxygen (14.5 psi) and at 25°C. At 45.5% conversion, tetralin was converted to 1-tetralone with 77.2% selectivity at room temperature and atmospheric pressure after 24 h. The catalyst recycles test and hot filtration experiment showed that oxidation proceeded through Ni(II) sites in LDH-[Ni-salen]. The catalysts were reused several times without losing their catalytic activity and selectivity. The present results may provide a convenient strategy for the preparation of 1-tetralone using layered double hydroxide-based heterogeneous catalyst at ambient temperature for industrial application in near future.
基金Supported by the 863 High-Technology Research and Development Program of China(No.2009AA03Z442)the National Natural Science Foundation of China(No.61077074)the Science and Technology Department of Jilin Province(No.20090422)
文摘Ternary In-rich AlxIn1-x N films were successfully grown on Si （111） and （0001） sapphire substrates by radio-frequency magnetron sputtering on a relatively Al-rich AlxIn1-x N layer after AlN buffer. X-ray diffraction （XRD） patterns of the films indicate highly c axis-oriented wurtzite structure and the indium content of about 0.76 has been evaluated according to the Vegard＇s law. An Al-rich AlxIn1-xN transition layer was formed between the ultimate In-rich AlxIn1-x N film and the AlN buffer, which served as a further buffer to alleviate mismatch. X-ray photoelectron spectroscopy （XPS） depth profiling analyses confirm the alternative of indium and aluminum composition and the unavoidable oxygen impurities from surface to bulk. Owing to high indium content, obvious E2u and InN-like Al （LO） phonon model accompanying with slight A1N-like A1 （LO） phonon model are observed. Hall effect measurements demonstrate n-type electrical conductivity in these alloys with carrier concentrations n=1019 cm-3. The strain in In-rich AlxIn1-x N films can be significantly reduced by introducing an Al-rich interlayer, facilitating the improvement of film quality for diverse device applications.
基金Project supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China (Grant No.2008ZX01002-002)the Major Program and the Key Program of National Natural Science Foundation of China (Grant Nos.60890191 and 60736033)
文摘The strain relaxation of an A1GaN barrier layer may be influenced by a thin cap layer above, and affects the transport properties of A1GaN/GaN heterostructures. Compared with the slight strain relaxation found in A1GaN barrier layer without cap layer, it is found that a thin cap layer can induce considerable changes of strain state in the A1GaN barrier layer. The degree of relaxation of the A1GaN layer significantly influences the transport properties of the two-dimensional electron gas （2DEG） in A1GaN/GaN heterostructures. It is observed that electron mobility decreases with the increasing degree of relaxation of the A1GaN barrier, which is believed to be the main cause of the deterioration of crystalline quality and morphology on the A1GaN/GaN interface. On the other hand, both GaN and A1N cap layers lead to a decrease in 2DEC density. The reduction of 2DEG caused by the GaN cap layer may be attributed to the additional negative polarization charges formed at the interface between CaN and A1GaN, while the reduction of the piezoelectric effect in the A1GaN layer results in the decrease of 2DEC density in the case of A1N cap layer.
文摘With the Uddeholm self restricted method, the effect of compound layer of plasma nitriding on thermal fatigue behavior of 4Cr5MoSiV1 steel was studied by the way of adding Ar during plasma nitriding to remove the compound layer. The results show that the compound layer of plasma nitriding can delay the nucleation of heat cracks and hold back the propagation of heat cracks from surface to substrate because of its high hardness and strength. On the other land, the heat checking expands faster with the compound layer on the surface than that without it. After 3000 cycles of thermal fatigue test, both heat cracks with the compound layer are wider than the another without compound layer and the number of heat cracks of the former is more from the view of cross section.
基金supported by Korea Research Institute of Standards and Science(KRISS–2019–GP2019-0014)。
文摘In or Ga gradients in the Cu(In1-xGax)Se2(CIGS)absorbing layer lead to change the lattice parameters of the absorbing layer,giving rise to the bandgap grading in the absorbing layer which is directly associated with the degree of absorbing ability of the CIGS solar cell.We tried to characterize the depth profile of the lattice parameters of the CIGS absorbing layer using a glancing incidence X-ray diffraction(GIXRD)technique,and then investigate the bandgap grading of the CIGS absorbing layer.When the glancing incident angle increased from 0.50 to 5.00°,the a and c lattice parameters of the CIGS absorbing layer gradually decreased from 5.7776(3)to 5.6905(2)?,and 11.3917(3)to 11.2114(2)?,respectively.The depth profile of the lattice parameters as a function of the incident angle was consistent with vertical variation in the compositionof In or Ga with depth in the absorbing layer.The variation of the lattice parameters was due to the difference between the ionic radius of In and Ga co-occupying at the same crystallographic site.According to the results of the depth profile of the refined parameters using GIXRD data,the bandgap of the CIGS absorber layer was graded over a range of 1.222-1.532 eV.This approach allows to determine the In or Ga gradients in the CIGS absorbing layer,and to nondestructively guess the bandgap depth profile through the refinement of the lattice parameters using GIXRD data on the assumption that the changes of the lattice parameters or unit-cell volume follow a good approximation to Vegard’s law.
基金Supported by Guangxi Hospital Preparation Quality Improvement Project of Zhuang and Yao Ethnic Medicines(GZZJ202015)Key Research and Development Plan of Guangxi Department of Science and Technology(GK AB21196057)+3 种基金High-level TCM Key Discipline(Zhuang Pharmacology)Construction Project of State Administration of Traditional Chinese Medicine(GZYYRJH[2022]226)Guangxi TCM Multidisciplinary Innovative Team Project(GZKJ2309)"Qingmiao Engineering"Talent Cultivation Project of Guangxi International Zhuang Medical Hospital(2022001)"High-level Talent Cultivation and Innovation Team"Project of Guangxi University of Chinese Medicine(2022A008).
文摘[Objectives]To establish the quality standard of hospital preparation Jiedu Shengxue granules.[Methods]Scleromitrion diffusum and Prunella vulgaris in Jiedu Shengxue granules were qualitatively identified by thin layer chromatography(TLC).A high performance liquid chromatography(HPLC)was established to determine the content of notoginsenoside R1 in the granule.[Results]The traditional Chinese medicinal materials in Jiedu Shengxue granules could be identified by TLC,and the characteristic spots were stable and clear.Notoginsenoside R1 had a good linear relationship in the range of 10.45-104.5μg/mL,with an average recovery of 98.52%and RSD=2.36%.[Conclusions]TLC and HPLC,as the quality control methods of Jiedu Shengxue granules,have high accuracy and good repeatability,which lays a foundation for the quality control of this mixture.
